Respiratory Mask

ABSTRACT

The invention relates to a respiratory mask comprising a mask body and an articulated connection piece that can be connected to a respiratory tube. On the mask body, at least one exhalation gap is located in the vicinity of a connection that holds the articulated connection piece. Preferably, the exhalation gap terminates in an umbrella-shaped outflow channel that runs away from the patient. Preferably, at least two components of the respiratory mask are interconnected without play.

The invention concerns a respiratory mask with a mask body and anarticulated connector that can be connected with a respiratory hose.

Respiratory masks are used, for example, in connection with ventilatorsto carry respiratory gas to the patient and to help carry away exhaledrespiratory gas. The respiratory mask is typically connected with theventilator by the respiratory hose.

A disadvantage of previously known respiratory masks is that theexhalation of the patient through the mask body and the respiratory hosecauses an acoustic effect that is unpleasant for the patient and personsin the vicinity. In addition, the exhaled stream of air produces a cooldraft that brushes along the patient's skin.

The objective of the present invention is to create a comfortable designof a respiratory mask that largely eliminates these unpleasant effectson the patient by the exhaled air.

In accordance with the invention, the solution to this problem ischaracterized by the fact that at least one exhalation gap is located inthe vicinity of the mask body, preferably in the vicinity of aconnection on the mask body that receives the articulated connector.

The respiratory mask of the invention, which is to be understood notonly as a single part but rather as an element of a complete ventilator,comprises a mask body and an articulated connector that can be connectedwith a respiratory hose, such that at least one exhalation gap islocated in the vicinity of the transition between the articulatedconnector and a connection on the mask body that receives thearticulated connector. In particular, the arrangement of the exhalationgap between the mask body and the connector keeps the noise level lowcompared to other positions in which it could be arranged. In thisposition of the exhalation gap, CO₂ is also washed out especiallyeffectively. Moreover, it is precisely in the area of transition betweenthe mask body and the connector that it is possible to provide a largegap length, which is acoustically especially advantageous compared, forexample, to holes and short slots.

The one or more exhalation gaps are preferably bounded by two outflowsurfaces each.

The articulated connector is advantageously designed as aball-and-socket joint and is supported on individual points, especiallyon two points, in a ball cage of the receiving connection. In this way,there is a slight amount of bearing friction, and easy mobility of theattached respiratory hose is guaranteed. Tolerances can also becompensated in a simple way.

In another advantageous embodiment of the respiratory mask, the one ormore respiratory gaps are bounded by the outflow surfaces, such thatthey are located adjacent to at least one spacing element and in thisregard are play-free or can even be provided with pretensioning relativeto each other. This prevents the occurrence of undesired vibrations andresonances due to escaping air when play is present, for especially inan exhalation gap in a ball-and-socket joint, a large gap length isobtained. Under certain circumstances, this could prove acousticallyunfavorable if moving parts are present in the gap.

In addition, the exhalation gap between two outflow surfaces can beproduced largely tolerance-free if the surfaces forming the gap arepressed against each other by a pretensioning force, thus eliminatingany play between them, and the height of the gap is adjusted by spacingelements between the surfaces. In a design of this type, the height ofthe gap depends, apart from the shape and positional tolerances of thesurfaces that form the gap, only on the tolerance of the height of a ribused as a spacing element. Since typical rib heights in exhalation gapsare 0.1-0.5 mm, gap tolerances of ±0.005 mm or less can be produced witha high degree of process reliability. Consequently, flow and soundemissions can be maintained within very narrow limits.

The mask body and the connector are preferably joined with a mechanicalcoding system. This has the advantage of preventing incorrect attachmentof the mask body and connector to each other and of preventing anincorrect combination of a connector with a mask body.

It is advantageous for the body of the mask and the connector to beattached to each other by a retaining ring with a locking device, forexample, a bayonet catch. The retaining ring also serves to fix theexhalation gaps, for example, by pretensioning the outflow surfaces ofthe respiratory mask and complementary outflow surfaces on the retainingring against each other.

In another advantageous embodiment of the respiratory mask, the outflowsurfaces form an outflow channel, which carries away the respiratory gasflow at an angle of 10-45°, especially 20-30°, and especially preferablyabout 25° to a plane arranged frontally with respect to the face of thepatient. In this way, the exhaled air is carried away from the patientin a basically umbrella-shaped path and is not unpleasantly perceived bythe patient.

In addition, the outflow channel can be designed in such a way that itprevents the flow of exhaled air from moving in the general direction ofthe patient's eyes, since a draft of air towards the eyes is felt asespecially unpleasant.

Furthermore, the respiratory mask can be designed in such a way thatsurfaces of the mask that bound the outflow channel are made of hardplastic, and surfaces of elements of the respiratory mask that arehandled are made of soft plastic. In this way, on the one hand, the flowof respiratory gas is reliably carried away, and, on the other hand, theease of handling and operating the respiratory mask is improved.

The invention is explained below with reference to the examplesillustrated in the figures.

FIG. 1 shows a perspective view of a respiratory mask designed as anasal mask.

FIG. 2 shows a view of the inside of the mask, as seen from the rear ofFIG. 1.

FIG. 3 shows a view of the outside of the mask, as seen from the frontof FIG. 1.

FIG. 4 shows a perspective view of the body of the mask in FIG. 1.

FIG. 5 shows a side view of the body of the mask.

FIG. 6 shows a cross section through the plane of symmetry of the bodyof the mask.

FIG. 7 shows a view of the retaining ring from the rear.

FIG. 8 shows a view of the retaining ring from the front.

FIG. 9 shows a perspective view of the retaining ring.

FIG. 10 shows a side view of the retaining ring.

FIG. 11 shows a cross-sectional view of the retaining ring from FIG. 10.

FIG. 12 shows a perspective view of the body of the mask.

FIG. 13 shows a partial view of an enlarged cross section through thebody of the mask in the vicinity of the ball-and-socket joint.

FIG. 14 shows an enlarged view of the detail XIV in FIG. 13.

FIG. 1 shows a respiratory mask that is designed as a nasal mask. Thebody 1 of the mask is made of a relatively strong material. The mask hasa protruding edge 2, which rests against the face of a patient (notshown) and provides the necessary seal. An angled connector 3 connectsthe body 1 of the mask with a rotatably supported sleeve 4, which isused to attach a respiratory gas hose (not shown). To guarantee securepositioning of the respiratory mask on the patient's head, a foreheadsupport 5 is used. The connector 3 and the mask body 1 are connectedwith each other by a ball-and-socket joint 18.

FIG. 2 shows the interior of the nasal mask from FIG. 1 in a directionof view from the inside towards a receptacle for the ball-and-socketjoint 18, which is not shown in this drawing. Two pressure measurementconnectors 9 are located in the upper area. Flow openings 7 lead toexhalation gaps 14 (not shown in this drawing). The flow openings 7 arebounded by flow guide structures 8, which are designed in such a waythat they cause the respiratory gas flow to converge and to be guidedinto the exhalation gaps 14. The flow guide structures 8 are preferablydesigned in such a way that the respiratory gas flow is guided infunnel-like fashion into the exhalation gaps 14. The flow guidestructures 8 in the upper region block the flow of respiratory gas inthe direction of the patient's eyes. Inclined surfaces 6 are provided tofacilitate the insertion of bayonet teeth 26 of a ball cage 24, which isnot shown in this drawing.

FIG. 3 shows the view of the outside of the mask from FIG. 1, as seenfrom the front of the mask. An outflow surface 10 is formed as a ring. Aretaining ring 31, which is not shown in this drawing, can be mountedand locked in place with the aid of ribs 11 and a catch 12.

FIG. 4 shows a perspective view of the body of the nasal mask. Acentering ring 13 is provided for mounting the retaining ring.Exhalation gaps 14 are located on the sides of the centering ring 13 andopen towards the outflow surface 10. The centering ring 13 has recesses15 that act as a mechanical coding system to prevent incorrect mountingof the retaining ring.

FIG. 5 shows a side view of the body of the mask. The mask body 1, thecentering ring 13, and the catch 12 are especially apparent in thisview.

FIG. 6 shows a cross section through the body of the mask from FIG. 5.The respiratory gas flow 17 moves along the flow guide structure 8 andinto the exhalation gap 14. The flow guide structure 8 is preferablydesigned in such a way that the respiratory gas flow is guided infunnel-like fashion into the exhalation gap 14. The exhalation gap isbounded by the flow guide surface 16. In the exhalation gap, therespiratory gas flow is deflected at least once on the flow guidesurface 16. Deflection of the respiratory gas flow can take place onlyin the exhalation gap 14, only in the area of transition of the maskbody 1 into the exhalation gap 14, or combined in both areas.

The respiratory gas flow moves from inside the respiratory mask tooutside the mask along the flow guide surface 16. After leaving theexhalation gap 14, which is the narrowest point, the respiratory gasflow leaves the respiratory mask in a fan-shaped flow path along theextended outflow surface 10. In this regard, the respiratory gas flowleaves the exhalation gap 14 at an angle alpha, which is preferably10-45° to the vertical in FIG. 6. This vertical plane coincides with aplane that runs frontally to the face of a patient (not shown here).

FIG. 7 shows a top view of a retaining ring 31 from the rear. It has awidth d of less than 7 mm, as indicated by a double arrow. Spacer ribs25 allow the retaining ring 31 to be mounted on the mask body 1 in thevicinity of the outflow surface 10 without play and with pretension. Inthe assembled state, the exhalation gap 14 is bounded by outflowsurfaces 28 on the retaining ring 31 and the outflow surface 10 on thebody 1 of the mask. A tab 20 on the retaining ring 31 is the complementto the catch 12 on the body 1 of the mask, so that additional securingof the retaining ring 31 on the body 1 of the mask is ensured. A surfacesegment 19 that rests on the outflow surface 10 in the assembled stateguarantees that no air can flow off in the direction of the patient'seyes. Slots 29 between the elements of the ball cage 24 allow easyassembly.

FIG. 8 shows a view of the retaining ring 31 from the front. The innerregion of the retaining ring 31 is made of a hard material 23, and theouter region is made of a soft material 22. Nubs 21 improve the grip.

FIG. 9 shows the retaining ring 31 in a rear perspective view. Thisviewing direction reveals the receptacle 30 for the web of the centeringring 13.

FIG. 10 shows a side view of the retaining ring 31 and provides a viewof the bayonet teeth 26.

FIG. 11 shows a cross-sectional view of the retaining ring 31 from FIG.10.

The functions of the individual components illustrated in FIG. 9 to FIG.11 will be explained again in detail later in connection with adescription of the assembly and disassembly of the individual componentsfor the specific purpose of further clarifying the mechanicalsignificance and functionality of the individual components.

The perspective view in FIG. 12 again illustrates the mask body 1 afterremoval of the forehead support 5, which is not shown in FIG. 12. In thetransition region between the outflow surface 10 and the centering ring13, especially the location of the exhalation gap 14 is once againevident. The exhalation gaps 14 have essentially rectangularcross-sectional shapes, and their longitudinal axes extend in thecircumferential direction of the outflow surface 10. The individualexhalation gaps 14 are separated from each other by spacing elements 32.The spacing elements 32 bring about a mechanical connection between thecentering ring 13 and the other material of the body 1 of the mask.

The exhalation gaps 14 are preferably arranged in such a way that theyextend in a region of the centering ring 13 that faces the outflowsurface 10. In this way, the respiratory gas emerging from theexhalation gaps 14 is guided directly into the area of the outflowsurface 10. After leaving the exhalation gaps 14, the respiratory gasflow is deflected on the wide and extended outflow surfaces 10, 28 andflows diffusely and quietly into the surrounding environment through theoutflow channel defined by the outflow surfaces.

FIG. 13 shows an enlarged partial cross-sectional view in the area oftransition between the ball-and-socket joint 18 and the retaining ring31 held by the mask body 1. An arched course of the ball cage 24 isespecially evident. The ball cage 24 extends concavely with a strongercurvature than a convexly shaped outer surface of the ball-and-socketjoint 18. In this way, the ball-and-socket joint 18 is acted upon onlyalong two guide lines, guide points 33, 34, or along linear segments ofthe ball cage 24. This makes it possible to compensate any productiontolerances that may be present in the vicinity of the surfaces of theball-and-socket joint 18 and/or the ball cage 24, since there is nosurface guidance of the components on each other. Spring tensioning ofthe ball-and-socket joint 18 inside the ball cage 24 is preferablyprovided, so that secure support of the ball-and-socket joint 18 alongthe guide lines 33, 34 is guaranteed.

FIG. 14 shows an enlarged section of the passage of the respiratory gasflow through the exhalation gap 14 along the flow guide surface 16 tothe surrounding environment see FIG. 6. The respiratory gas flow 17enters the exhalation gap 14, for example, in funnel-like fashion. Theexhalation gap is bounded by the flow guide surface 16. In theexhalation gap, the respiratory gas flow is deflected at least once onthe flow guide surface 16. The respiratory gas flow is guided from theinside of the respiratory mask to the outside along the flow guidesurface 16. During the passage of the respiratory gas flow through theexhalation gap 14 along the flow guide surface 16 to the surroundingenvironment, the respiratory gas flow is deflected at an angle beta (β),which is preferably arranged 1-15° to a vertical line 38. This verticalline stands essentially at an angle of 90° perpendicularly to the planeformed by the parts of the body of the mask that bound the exhalationgap. During the passage of the respiratory gas flow through theexhalation gap 14 along the flow guide surface 16 to the surroundingenvironment, it is especially preferred for the respiratory gas flow tobe deflected at an angle beta (β) arranged 2-7° to a vertical line 38.

To provide further explanation of the function of the individualcomponents, we shall now explain the assembly of the individual parts,starting from their unassembled state. This assembly can also be easilymanaged by the patient himself. In a first step, the mask body 1, whichis made of the harder material, and the protruding edge 2 of the maskare fitted together. To this end, the protruding edge 2 of the mask hasa U-shaped profile that is not evident in the drawings. This U-shapedprofile is pushed onto an edge of the body 1 of the mask. In the area ofthe point of contact between the protruding edge of the mask and thebody of the mask, there is at least one undercut and at least oneprojection complementary to the undercut. The undercut is preferablylocated in the area of the softer component. The interaction of theundercut and projection in the assembled state provides a secureconnection.

In the next assembly step, for example, a shaft 35 of the foreheadsupport 2 can be inserted in a mounting support 36 of the mask body 1and secured by means of at least one fastening device 37. However, theassembly of the forehead support 5 can also be carried out at any otherdesired point of the assembly operation.

In another assembly step, the retaining ring 31 is pushed onto theconnector 3, starting from the sleeve 4, and is positioned in the areaof the ball-and-socket joint 18. As the retaining ring 31 is beingpushed onto the connector 3, it has an orientation such that, after theplacement operation has been completed, the bayonet teeth 26 point inthe direction away from the sleeve 4, and the ball-and-socket joint 18is partially enclosed by the ball cage 24 of the retaining ring 31.

In a final assembly step, the retaining ring 31 is positioned, togetherwith the connector 3, in the vicinity of the centering ring 13 of thebody 1 of the mask. Due to the asymmetrical arrangement of the ribs 11along the periphery, as shown, for example, in FIG. 3, and thecorresponding arrangement of the bayonet teeth 26, the bayonet teeth 26can be inserted in the recesses 37 between the ribs 11 only in a singlepredetermined position. This creates a mechanical coding system.

After the bayonet teeth 26 have been inserted in the recesses 37 betweenthe ribs 11, the retaining ring 31 is twisted relative to the body 1 ofthe mask in such a way that the catch 12 is engaged. The catch 12 ispreferably designed as a projection of the retaining ring 31 thatengages a corresponding recess in the mask body 1. In principle,however, the device can also be constructed in the opposite way. Elasticengagement of the catch 12 is assisted if the retaining ring 31 is madeof a relatively soft material, so that the likewise soft projection ofthe retaining ring 31 can be inserted in the recess of the mask body 1and can also be twisted back out again.

After the retaining ring 31 has been twisted relative to the mask body1, the assembly operation is complete. The final position of theretaining ring 31 is predetermined by a lateral stop of the bayonetteeth 26 on the ribs 11. In addition, the bayonet teeth 26 engage behindthe ribs 11, so that the total unit is also able to withstand tensileloads. The respiratory mask is disassembled in the reverse order ofassembly described above.

As a result of the design of the retaining ring 31, it can be mounted onthe mask body 1 without play and, if necessary, with pretensioning.Consequently, the width of the exhalation gap or gaps 14 now dependsonly on the tolerance of the height of the spacer ribs 25. Theexhalation gap 14 is thus realized in a way that is extremely uniformand largely independent of tolerance. This in turn means that thedischarge of the respiratory gas through the exhalation gap 14 isextremely constant and thus that the sound emissions produced by thisdischarge are likewise extremely constant.

The design of the retaining ring 31 allows the ball-and-socket joint 18to be inserted in the elastic ball cage 24 of the retaining ring 31 andallows the ball cage 24 to enclose the ball-and-socket joint 18 at leastpartially. The ball-and-socket joint 18 is secured in the ball cage 24by inserting the centering ring 13 in the receptacle 30 present in theretaining ring 31. As a result, the elastic elements of the ball cage 24are bounded on one side by the ball-and-socket joint 18 and on the otherside by the centering ring 13. In the assembled state, theball-and-socket joint is secured in the area of the mask in this way.The mobility of the ball-and-socket joint, on the one hand, and the sealrelative to the respiratory gas in the area between the ball-and-socketjoint and the ball cage, on the other hand, are determined by the exactdimensioning and narrow tolerances.

1. A respiratory mask with a mask body and an articulated connector thatcan be connected with a respiratory hose, wherein at least oneexhalation gap (14) is located in the vicinity of the mask body (1). 2.A respiratory mask in accordance with claim 1, wherein the exhalationgap (14) is located in the vicinity of a connection on the mask bodythat receives the articulated connector (18).
 3. A respiratory mask inaccordance with claim 1, wherein the articulated connector (18) isdesigned as a ball-and-socket joint.
 4. A respiratory mask in accordancewith claim 3, wherein the ball-and-socket joint (18) rests on individualpoints, especially along two guide lines (33, 34), in a ball cage (24)of a receiving retaining ring (31).
 5. A respiratory mask in accordancewith claim 1, wherein the outflow surfaces (10, 28) that bound theoutflow channel are arranged adjacent to at least one spacing element(25) and are play-free or are provided with pretensioning relative toeach other.
 6. A respiratory mask in accordance with claim 5, wherein amechanical coding system is provided for joining the mask body (1) andthe connector (18).
 7. A respiratory mask in accordance with claim 1,wherein the mask body (1) and the connector (18) are secured relative toeach other by the retaining ring (31) with a bayonet catch (6, 26).
 8. Arespiratory mask in accordance with claim 1, wherein the outflowsurfaces (10, 28) bound an outflow channel, which carries away therespiratory gas flow (17) at an angle alpha of 10-45° with respect to aplane that runs frontally to the face of a patient.
 9. A respiratorymask in accordance with claim 1, wherein the outflow channel provides adischarge of the respiratory gas flow (17) that avoids a segment in thedirection of the patient's eyes.
 10. A respiratory mask in accordancewith claim 1, wherein surfaces of the respiratory mask that bound theoutflow channel are made of hard plastic, and surfaces of elements ofthe respiratory mask that are handled are made of soft plastic.
 11. Arespiratory mask in accordance with claim 1, wherein the angle α is inthe range of 20-30°.
 12. A respiratory mask in accordance with claim 1,wherein the angle α has a value of about 25°.
 13. A respiratory mask inaccordance with claim 1, wherein ribs (11) for securing the retainingring (31) are arranged asymmetrically along the periphery of a passageopening in the area of the mask body (1).
 14. A respiratory mask inaccordance with claim 13, wherein bayonet teeth (26) of the retainingring (31) are arranged asymmetrically along the periphery of theretaining ring (31), corresponding with the ribs (11).
 15. A respiratorymask in accordance with claim 1, wherein recesses (37) for receiving thebayonet teeth (26) extend in the circumferential direction between atleast two ribs (11).
 16. A respiratory mask in accordance with claim 1,wherein at least one catch (12) is provided for locking the retainingring (31) relative to the body (1) of the mask.
 17. A respiratory maskin accordance with claim 1, wherein the ball cage (24) formed by theretaining ring (31) for the ball-and-socket joint (18) consists of aplurality of individual thin plates.
 18. A respiratory mask with a maskbody and an articulated connector that can be connected with arespiratory hose, wherein at least two components of the respiratorymask are connected with each other without play.
 19. A respiratory maskin accordance with claim 18, wherein the freedom from play is realizedby contact between the components at no more than three points.
 20. Arespiratory mask in accordance with claim 18, wherein the freedom fromplay is realized by contact between the parts along two guide lines (33,34).
 21. A respiratory mask in accordance with claim 18, wherein thecomponents are elastically tensioned against each other.
 22. Arespiratory mask with a mask body and an articulated connector that canbe connected with a respiratory hose, wherein an outflow channel forexhaled gas is essentially umbrella-shaped and is oriented in adirection that faces away from the protruding edge (2) of the mask. 23.A respiratory mask in accordance with claim 22, wherein the outflowchannel extends at least in certain areas at an angle in the range of10-45° relative to a plane spanned by the protruding edge (2) of themask.
 24. A respiratory mask in accordance with claim 1, wherein theexhalation gap (14) opens into an outflow channel bounded by two outflowsurfaces (10, 28).
 25. A respiratory mask with a mask body and at leastone outflow channel in the vicinity of the mask body, wherein, duringits passage from the inside of the mask body (1) through at least oneexhalation gap (14) along at least one flow guide surface (16) to theoutside environment, the respiratory gas flow is deflected at least onceby more than 2° (angle β) from a vertical line (38), which isessentially perpendicular to the plane of the mask body.
 26. Arespiratory mask in accordance with claim 25, wherein, during itspassage from the inside of the mask body through at least one exhalationgap (14) along at least one flow guide surface (16) to the outsideenvironment, the respiratory gas flow is deflected at least once by lessthan 7° (angle β) from a vertical line (38), which is essentiallyperpendicular to the plane of the mask body.
 27. A respiratory mask witha mask body and at least one outflow channel in the vicinity of the maskbody, wherein the respiratory gas flow is guided in funnel-like fashionfrom the inside of the mask body into at least one exhalation gap (14)and in the area of an outflow channel flows off to the outsideenvironment in a fan-shaped path.
 28. A respiratory mask with a maskbody and at least one outflow channel in the vicinity of the mask body,wherein the respiratory gas enters the outflow channel from the insideof the mask body through at least one exhalation gap (14) along at leastone outflow surface (10), and the flow channel expands towards theexterior surface of the mask body.
 29. A respiratory mask with a maskbody and at least one ball-and-socket joint (18), which is at leastpartially enclosed on the outside by a ball cage (24), wherein theball-and-socket joint (18) is secured in the ball cage (24) by acentering ring (13), which rests against at least certain outside areasof the ball cage (14).
 30. A respiratory mask with a mask body and atleast one ball-and-socket joint (18), which is at least partiallyenclosed on the outside by a ball cage (24), wherein the ball-and-socketjoint (18) in the ball cage (24) rests permanently on fewer than fourpoints.
 31. A respiratory mask with a mask body and at least oneball-and-socket joint (18), which is at least partially enclosed on theoutside by a ball cage (24), wherein the ball cage (24) extendsconcavely with a stronger curvature than a convexly shaped outer surfaceof the ball-and-socket joint (18).